1. Field of the Invention
The invention relates to lawnmowers and to cutter decks usable there with. More particularly, the invention relates to a locator assembly for a lawnmower cutter deck.
2. Discussion of the Related Art
Riding lawnmowers and some larger walk behind lawnmowers have multi-bladed cutter decks supporting two, three, or even more cutting blades. Such lawnmowers may cut a strip of grass from 24 inches to 72 inches wide or even more. The cutter deck typically can be raised from a cutting height located near the ground to a travel height located above the ground. The cutting height also can be adjusted by raising or lowering the cutter deck through a more limited stroke and latching the cutter deck in position.
The cutter deck of any lawnmower must be positioned generally parallel to the ground to maintain an even cut. Factors such as initial manufacturing tolerances and subsequent wear in the lawnmower frame, the cutter deck, and the cutter deck supports hinder cutter deck leveling both at initial manufacture and over time. Many cutter decks therefore incorporate some mechanism to perform limited “leveling” of the cutter deck. For instance, some lawnmowers permit “pitch” or “fore and aft” leveling by adjusting the length of adjustable links coupling front and rear cranks to one another. The cranks are rotated in unison during normal operation to move the deck between its cutting and transport positions and to vary the cutting height. By rotating the front and rear cranks relative to one another, the heights of the upper end of the deck supports at the front and rear of the deck are altered relative to one another, altering deck pitch.
Cutter decks often are suspended from the lawnmower frame by chains. In this case, pitch adjustment adjusts the height of the upper ends of the front chains relative to the rear chains. Being flexible, the chains permit the deck to rise up and over an obstruction upon contact without interference from the structure coupling the cutter deck to the lawnmower frame, thus preventing or inhibiting damage to the deck upon encountering obstructions and inhibiting scalping of the grass. However, because the chains lack rigidity in all planes, the deck may sway fore and aft and/or side-to-side during cutting, resulting in uneven cuts. For this reason, so-called locators are sometimes provided that link the cutter deck to the frame so as to allow the deck to move vertically relative of the frame while preventing or at least inhibiting fore and aft or side-to-side motion. However, the links forming these locators, when provided, are typically inflexible. They therefore can accommodate little, if any, relative side-to-side or fore and aft motion between the deck and the frame. This may result in damage to the cutter deck upon encountering an obstruction. In addition, in allowing only vertical movement of the cutter deck, some decks cannot tilt to accommodate changes in surface topography.
Some of these problems have been recognized prior to development of this invention, but prior attempted solutions proved inadequate and/or raised new problems that have yet to be addressed.
For instance, U.S. Pat. No. 6,079,193 to O'Neill et al. discloses a lawnmower suspension system with a lost motion connection that allows limited side-to-side movement of a front-mounted cutter deck. The cutter deck is mounted on the lawnmower frame by first and second opposed arms. Each of the arms is coupled to the frame by a lost motion coupling in the form of an oversized sleeve that receives a relatively small-diameter pin. The circumferential clearance between the pin and the sleeve permits limited vertical movement of the cutter deck relative to the frame, and the axial clearance between the end of the pin in the end of the sleeve permits limited side-to-side movement of the deck relative to the frame. While this arrangement permits both vertical and lateral movement of the deck relative of the frame, it couples the two movements together and, as a result, prevents or inhibits pivoting of the deck relative of the frame. The lost motion coupling is also relatively complex to manufacture and assemble and risks invasion by dirt and debris. It also is not usable with widely-used center-mounted cutter decks that are suspended from the frame by chains or other flexible couplings.
Other systems, such as the one disclosed in U.S. Pat. No. 4,700,536 to Torras, permit pivoting motion of the cutter deck relative to the frame but do not permit side-to-side or vertical motion of the cutter deck relative to the frame.
The need therefore exists to provide a deck locator for a suspended cutter deck that permits limited side-to-side movement of a cutter deck relative to a frame independently of any vertical or pivoting movement.
The need also exists to provide a deck locator that is robust, easy to install, and simple to maintain.